Background: The majority of the literature now has shown no association between vasectomy and prostate cancer. The effect of vasectomy on men with a family history of prostate cancer or on those who underwent a vasectomy at a young age or had an extended period of time since the procedure has been poorly studied due to small sample sizes and short study follow-up.

Objective: To assess the risk of prostate cancer in men by age and length of time to exposure from vasectomy to disease.

Design: Population-based, prostate cancer case-controlled study.

Participants: 1327 men aged 35 to 74 years residing in King County, Washington, with a diagnosis of prostate cancer.

Methods: Cases of prostate cancer were identified from the SEER database for this population. Structured in-person interviews were conducted. Eligible controls were identified by random digit telephone dialing. Analysis based on prostate cancer Gleason score and stage was performed. Analysis was also performed based on demographics, age, prostate cancer screening history (within the last 5 years), family history of prostate cancer, and vasectomy parameters.

Results: 1327 men were eligible for study from the SEER database; 1001 completed the personal questionnaire. In total, 1340 controls were identified, of which 942 were interviewed. The control population showed that men who had undergone vasectomy were older, white, married, non-smokers with higher income and education, and had undergone PSA screening. Of men with prostate cancer and controls, 36% had undergone a vasectomy. Mean number of years since vasectomy in cases and controls was 21.1 years. No significant association was seen between prostate cancer and vasectomy status, age at vasectomy, years since vasectomy, or year of vasectomy. There was no evidence of risk estimates across vasectomy parameters. Risk did not change if men with prostate cancer within 2 years of vasectomy and controls with no PSA screening within 5 years (n=136) were excluded.

Conclusions:

No association was found between prostate cancer and vasectomy, even in men who had a vasectomy performed at a young age or had an extended period of time since vasectomy.

Reviewer’s Comments: This paper is a well-conducted, large case-control study that answers the concern about possible limitations of previous work that reported the lack of association between prostate cancer and vasectomy. This criticism often indicated inadequate follow-up since vasectomy to make this claim. In this study, average time since vasectomy in cases of prostate cancer and controls was 21 years. Multiple variables were looked at including vasectomy in the face of prostate cancer family history and screening. This large study should end the criticism on previous work that did not answer the question of prostate cancer and time from vasectomy. (Reviewer–Ajay K. Nangia, MBBS).